Furnace.



No. 742,612.. PATENTED 00T. 27, 1903.

' F. J. DOYLE.

FUR'NAGE.

APPLICATION FILED MAR. 5, 1903.

N0 MODEL.

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ivo. 742,612.

UNTTED STATES Patented October 27, 1303.

PATENT Cierres.

FU RNACE.

SPECIFICATION forming part of Letters Patent No. 742,612, dated October 27, 1903. Application led March 5, 1903. Serial No. 146.312. (No model.)

To a/ZZ whom t may concern:

Be it known that 1, FRANcIs J. DoYLE, of the city of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Furnaces, of which the following is a specification. v

This invention relates to improvements in furnaces, and refers more specifically to an improved furnace particularly adapted for economically converting fuel into heat for the purpose of generating steam, the furnace being of that type wherein the products of combustion are circulated progressively through circulating passages and are successively supplied with quantities of heated air to promote the combustion.

The object of the invention is to provide a simple, compact, and cheap construction capable of effecting the most perfect combustion of the fuel and so constructed andfarranged as to produce a most intense combustion and to prevent to the greatest possible extent a loss of heat by radiation.

To this end the invention consists in the matters hereinafter described, and more particularly pointed out in the appended claims, and the same will be more readily understood from the following description, reference being had to the accompanying drawings,"

wherein- Figure 1 is a vertical axial sectional view of a furnace constituting a preferred embodiment of my invention. Fig. 2 isa similar view showing the furnace `adapted to a horizontal boiler. Fig. 3 is a sectional view taken on line 3 3 of Fig. 1 and looking in the direction of the arrows. Fig. l is a sectional view taken on line 4 4 of Fig. 1 and looking in the direction of the arrows.

Referring to said drawings, designates as a whole the-furnace, so constructed as to form two main chambers, the lower chamber constituting the fire-box 11 and ash-pit 12, and the upper chamber (designated as awhole 13) constituting the combustion chamber, within which the products of combustion are circulated and then discharged 1o the main iiue 14, leading to the boiler.

-In the preferred embodiment shown herein the furnace has cylindric side walls, the firebox being formed by an inner wall-15, which extends across the interior of the furnace, as at 16, to form the top wall of the fire-box and is provided in said top wall with a main outlet-aperture 17 and a plurality of smaller airinlets 13, dispersed circumfeientially around the main outlet 17. The grate 19 is arranged to extend across the interior of the furnace at the lower end of the fire-box, as usual, the several grate-bars thereof being supported in anyY suitable manner-as, for example, by cross-bars 2O and 21. furnace, within which the fire-box and ash-pit are located, is constructed of three separate walls, as 15, 22, and 23, arranged concentrically with each other and spaced apart, so as to provide intervening air-spaces 24 and 25, the two outer walls 22 and 23 being continued up through the full height of the furnace, over the top of the same, and returned a short distance, as will be hereinafter more fully described. Preferably, and as shown herein, the two inner walls and 22 will be constructed of-fire-brick or other suitable refractory material, so as to be capable of suitably withstanding the heat of the furnace, while the outer wall may be constructed of sheet or plate iron.

26 and 27 designate air-inlet ilues arranged to communicate with the spaces 24 and 25, respectively, a plurality of such inlet-lines being provided, leading into said spaces at intervals apart around the circumference of the furnace.

The walls 22 and 23 at the top of the furnace are curved inwardly and returned down- Y wardly to form an annular space 23, surrounding a central, circular, and extending or tubelike outlet-flue 29, of which the flue Mforms a continuation. The central returned portion 29 extends downwardly somewhat less than one-half the height or depth of the combustion chamber, and at the lower end of said extension the outer wall 23 is deflected outwardly, so as to cross the end of the annular air-space 25, extending between said outer wall andthe adjacent inner wall, as indicated at 30. The wall 22 is, however, continued some distance beyond the termination of the outer wall and then across the central part of the furnace to form a partition 31, concave above and convex beneath.

near the bottom of the furnace,

The lower part of the ICO Vithin the irregularly-shaped combustionchamber 13 thus formed is arranged a hollow annulus 32, the upper part of which extends upwardly within the annular part 2S of the combustion-chamber and the lower part of which is located within the central lower part of the combustion-chamber, said annulus being conveniently supported in part by means of a cylindric wall 33, forming a liuc or passage 34, concentric and in continuation of the outlet-passage 17 of the fire-box. The crosssectional space of said annulus is such as to divide the interior of the combustion-chamber into annular circulating-passages which extend completely around said annulus, the flue or passage 34 discharging into the circulating-passage 35, intervening between the upper and inner surface of the annulus and the opposite wall portions 31 and 22 of the furnace.

3o' designates a plurality of intersecting ilues arranged to extend obliquely upwardly and inwardly from the lower outer portions of the combustion chamber through the lower parts of the annulus and through the partition-wall 3l, thereby affording communication between said lower part of the combustion-chamber and the space immediately below and communicating with the main outletiue 29. A partition-wall 37 is provided arranged to extend over and parallel to the top wall 1G of the fire-box from the wall 22 to the flue-wall 33, so as to provide an extension or continuation of the air-space 24 over the top of the fire-box, and preferably said wall 37 is extended upwardly around the Hue-wall to the bottom of the annulus Preferably also that part of the wall 22 which incloses the lower part of the combustion-chamber is provided with a lining 3S, of metal, said lining in the present instance extending from the wall 37 upwardly to a point coextensive with the top of the annulus, as indicated clearly in the drawings.

In order to supply the hollow annulus with heated air, a plurality of tlues 39 are arranged to extend from the wall 37 upwardly to and through the bottom of the annulus, said iiues being spaced at intervals around the furnace and arranged to communicate with the airspace 24, as indicated clearly in the drawings. In this connection it is to be noted that the fines 30 will be so located as to communicate with the annulus at points between the several intersecting flues 36, h'ereinbefore described, which latter, it will be understood, have no communication with the interior of the annulus. The side walls of the annulus are provided with numerous outlet-apertures 40, through which the heated air is discharged through the circulating-passages 35, hereinbefore described.

In order to provide a final supply of heated air to the products of combustion after they have passed through the circulating-passages and entered the discharge Hue 20, the side walls of the latter are provided with apertures 50, provided at their arranged to extend from the upper part of the 7 5 fire-box obliquely upwardl fand radially outward through the several walls of the furnace and being extended beyond the latter suii ciently to contain a pair of feed controlling slides 43 44, which are capable of being oper- 8o ated in such manner as to feed the fuel into the furnace in successive measured quantities or charges. As a convenient means of thus operating said slides a bracket-support 45 is mounted upon the lower beyond the outer end of which is pivotally mounted a lever 46 at a point intermediate of its length, the ends of said lever having slotand-pin connections with the ends of the reside of each chute,

speetive slides 43 44, so that the latter will be 9c projected and retracted from the chute alternately as the lever is oscillated. Any suitable means maybe employed for actuating the lever 4G-as, for example, by means of a suitable handle 47-or supplied for actuating these levers automatically from any suitable motor.

In order that the condition of the fire within the lire-box may be inspected, a plurality of peepholes 48 are provided, arranged to extend through the several walls of the furnace and opening into the upper part of said firebox, said peep -holes being conveniently formed by means of tube-sections 4f), inserted mechanism may be through suitable apertures in the several walls and normally closed by means of plugs inner ends with refractory portions 5l, which serve to protect both the tube-sections and the plugs from destruction by the intense heat.

In addition to the feed-chutes thc fire-box is desirably provided with a door 52, through which access may be had to its interior for the purpose of inspection, stoking, and rcpair, and likewise the ash-pit is provided with a suitable opening 53, leading out through the side walls of the furnace and closed by means of an ordinary door 54. The door 54 is provided with the usual air-inlets 55, controlled by means of a slide-damper 56, whereby air may be admitted to a space below the grate in controlled quantities.

Inasmuch as it is desirable to provide for a direct draft from the .fire-box or initial combustion-chamber to the main Hue the time the fire in the furnaceis being started, a passage 57 is formed through the wall 3l in alinement with the passages 17 and 34, which passage 57 is controlled by a damper 5S, operable by means of a rod its upper side and extending upwardly through the flue 29 and out through the top wall of the furnace. The rod 59 may be reciprocated by any suitable means as, for

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during 1 25 59, connected with 13a ucts of combustion example, by means of a hand-lever GO-connected therewith and pivotally mounted upon a support 61. (See Fig. 2.)

Theoperation of the furnace constructed and arranged as thus described may be brieiiy detailed as follows: After the fire has been suitably started in the fire -box and the damper 57 closed the air-inlets communicating with the space below the grate are so adjusted as to admit a restricted supply of air, and a sufficient quantity of fuel is charged into the fire-box to produce a restricted combustion,which results in distilling and throwing off the combustible gases, but does not produce a free combustion within the fire-box. rlhe gases and products of combustion rise from the fire-box through the main outlet 17 and communicating passages 34 and pass into the circulating passages 35, an initial supply of air being entrained through theseveral inlets 18 in the top wall of the furnace and a further supply of air being added to the gases directly from the annular airspace 24, where the latter intersects the passages 17 and 34. The products of combustion are deflected wardly by means of the convex lower surface of the wall 31 and pass upwardly within the circulating-passages 35, around the hollow annulus, receiving additional suppliesv of heated air throughout practically their entire course of progress through the circulating-passages 35. From the lower portions of the combustible chamber the gases pass upwardly through the fines 36 into the space immediately above the partition 31, and thence into the main outlet-nues 29 and 14, receiving an additional supply of heated air while passing through the flue portion 29.

It will be seen that the air supplied from the annular space 24 is heated during its passage upwardly adjacent to thewalls of the fire-box, so that the air supplied to the prodboth in the upper part of the'iire-box and at the entrance to the combustion-chamber is in heated condition. Inasmuch also as the air supplied to the hollow annul us is from the same source, this air reaches the annulus in heated condition; but in view of the fact that the latter is completely enveloped by the circulating-passages within which the combustion is taking place the air within the annulus will be raised to a substantially higher temperature before it escapes into said circulating-passages. that the free combustion which is inaugurated at the entrance to the combustion-chamber is intensified progressively as the gases circulate through the combustion-chamber. The final supply of Aair added to the products of combustion at the entrance to the dischargeflue 29 is likewise heated to an intense temperature, since this air passes'upwardly between the walls of the furnace throughout the entire height of the latter, passing lastlyl through that part of the hollow furnace-wall which incloses the combustion-chamber and -hollow annulus.

tubes 64 of the boiler communicate.

radially outwardly and up- The result isA the inner side of which isobviously at a very high temperature, so that this final supply of air is even hotter than that supplied from the From the main dischargeflue 14 the products of combustion are conveyed to the device wherein the heat is to be utilized.

In Fig. 2 I have shown the application of a furnace constructed substantially like that hereinbefore described to a horizontal tubular boiler. In said figure the discharge-flue 14 is shown as extended from the top of the furnace downwardly to a point on a level with the main body of the boiler, (designated as a whole 62,) at which point it communicates with a chamber 63, formed at the front end of the boiler, with which the several horizontal fire- The boiler is inclosed in a suitable casing 65, so constructed as to provide the chamber 63, hereinbefore referred to, at the front end of the boiler, a corresponding chamber 66 at the opposite end of the boiler, and a lower chamber 67 beneath the boiler, desirably provided with a oor-wall 68, inclined from the rear end of the boiler obliquely forwardly and upwardly to a point adjacent to the lower side of the boiler proper. A smoke-stack or chimney 69 is arranged to communicate with the intertubular space of the boiler at the upper side thereof, this sm oke-stack being desirably located at the front of said boiler and arranged to communicate when desired with the front chamber 63 through a passage 70, normally closed by means of a damper 71.

The circulation of thev heated gases through the boiler is as follows: From the chamber 63 the gases pass rearwardly through the several fire-tubes of the boiler to the chamber 66,

thence downwardly to the chamber 67, and

up through the intertubular' space of the boiler to the smoke-stack. In case it be desired to cut out the circulation through the boiler and provide a direct draft tothe chimney the damper 71 may be simply raised, thus throwing the chamber 63 into direct communication with the smoke-stack.

In the present instance means are provided for heating the supply of air which is admitted to the fuel through the grate. To this end the air tube or trunk 72 is arranged to extend through the chamber 63, preferably arranged horizontally, the ends thereof being'open to the external air. From this trunk a pipe 73 extends forwardly and out through the side wall of the flue 14 and is there connected with a downtakeflue 7 4, which extends downwardly to a point opposite the ash-pit, andis then extended inwardly through the walls of the furnace and opens into said ash-pit.

The operation of the furnace shown in said Fig. 2 is obviously the same as that previously described and neednot,therefore,be repeated. In this connection, however, it will be noted that the main flue 14, as well also as that part of the boiler-setting which incloses the chamber GS, is inclosed within an outer wall 75,

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which forms therewith an air-space 76, communicating at the juncture of the flue 14 with the top of the furnace, with the air-space 24 of the latter. lf desired, a blower pipe, as indicated at 77, may be arranged to communicate with the annular' space 7 6 thus provided, whereby the final supply of air admitted through the inlets 4l maybe admitted under pressure. Obviously in view of the fact that this air is passed through the annular space inclosing the entire length of the outlet-Hue ll it will be brought to a high temperature before being discharged.

IVhile I have herein shown 'and described what I deem to be preferred embodiments of my invention, yet it will be understood that the details thereof may be modified without departing' from the spirit of the invention, and I do not, therefore, wish to be limited to these details except to the extent that they are made the subject of specific claims.

I claim as my inventionl. A furnace provided with a centrally-depressed top wall portion constituting an outlet-line, a combuStien-chamber immediately beneath said top wall portion and having its upper portion surrounding the centrally-depressed top wall portion, an annulus supported within said combustion-chamber and dividing the interior thereof into annular circulating-passages, a partition-wall extending across beneath the receiving end of said outlet-due and separating the latter from the combustionchamber, intersecting lines cxtendinfrom the circulating-passages exterior to the annulus, through said partition-wall and discharginginto the receiving end of said outlet-fine and a fire-box provided with a restricted outlet discharging into the circulating-passages of the combustion-chamber at a point inside of said annulus.

2. A furnace provided with a centrally-depressed top wall portion constituting an outlet-Hue, a combustion-chamber immediately beneath said top wall portion and having its upper portion surrounding the centrally-depressed top wall portion, an annulus supported within said combustion-chamber and dividing the interior thereof into annular circulating-passages, a partition-wall extending across beneath the receiving end of said outlet-flue and separating the latter from the combustion-chamber, intersecting flues extending from the circulating-passages exterior to the annulus, through said partition-wall and discharging into the receiving end of said outlet-Hue, a .tire-box provided with a restricted outlet discharging into the circulating-passages of the combustion-chamber at a point inside of said annulus, and means for supplying heated air to the products of combustion at the entrance to the combustionchamber and from the annulus.

3. A furnace provided with a centrally-dcpressed top Wall portion constituting an outa combustion-chambcr innnediatelyl let-liuc,

beneath said top wall portion and having its upper portion surrounding the centrally-depressed top wall portion, an annulus supported within said combustion-chamber and dividing the interior thereof into annular circulating-passages, a partition-wall extending across beneath the receiving end of said outlet-flue and separating the latter from the combustion-chamber, intersecting fines extending from thecirculating-passagesexterior to the annulus, through said partition-wall and discharging into the receiving end of said outlet-flue, a fire-box provided with a restricted outlet discharging into the circulating-passages of the combustion-chamber at a point inside of said annulus, and means for supplying heated air to the products of combustion at the entrance to the combustionchamber, from the hollow annulus at points throughout the circulating-passages and at the receiving end of the main outlet-fine.

4. A furnace provided with a centrally-dcpressed top Wall portion constituting an outlet-fine, a combustion-chamber immediately beneath said top wall portion and having' its upper portion surrounding the centrally-depressed top Wall portion, a hollow annulus supported within said combustion-chamber and dividing the interior thereof into annular circulating-passages, a partition-wall extending across beneath the receiving end of said outlet-fine and separating the latter from the combustion-chamber, intersecting flues extending from the circulating-passages exterior to the annulus, through said partition- Wall and discharging into the receiving end of said outlet-flue, a fire-box provided with a re-4 stricted outlet discharging into the circulating-passages of the combustion-chamber at a point inside of said annulus, and an annular conduit surrounding said fire-box, provided with an air-inlet near its lower end and with dischargeoutlets communicating with the discharge-outlet of the fire-box and with the hollow annulus respectively.

5. A furnace provided with a centrally-depressed top wall portion constituting an outlet-flue, a combustion-chamber immediately beneath said top wall portion and having its upper portion surrounding the centrally-depressed top wall portion, a hollow annulus supported within said combustion-chamber and dividing the interior thereof into annular circulating-passages, a partition-wall extending across beneath the receiving end of said outlet-fine and formed in continuation of the depressed central wall intersecting flues extending from portions of the circulating-passages exterior to the annulus through portions of the circulating-passages inside said annulus and discharging into said outlet-Hue, a fire-box provided with a restricted outlet discharging into the circulating-passages of the combustion-chamber ata point inside of said annulus, the outer walls of said furnace comprising two concenportion of the furnace,

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tric wall members spaced at an interval apart whereby an intervening air-heating conduit is formed, provided at its lower end with one or more inlets and provided in its portions which form the outlet-flue with dischargeopenings communicating with said flue, substantially as described.

G. A furnace provided with a centrally-depressed top wall portion constituting an outlet-iiue, a combustion-chamber immediately beneath said top wall portion and having its upper portion surrounding the centrally-depressed top wall portion, a hollow annulus supported within said combustion-chamber and dividing the interior thereof into annular circulatin g-passages', a partition-wall extending across beneath the receiving end of said outlet-iiue and'formed in continuation of the depressed central wall portion of the furnace, intersecting iues extending from portions of the circulating-passages exterior to the annulus through portions of the circulating-passages inside said annulus and discharging into said outlet-flue, a iire-box provided with a restricted outlet discharging into the circulating-passages of the combustion-chamber at a point inside of said annulus, the outer walls of said -furnace being of double construction separated by an air-heating space, and the wallsv of the ire-potl portion of the furnace being of three-part construction,the inner wall member separated from the adjacent wall member by an annular air-space provided with one or more outlets at its lower end and arranged to discharge into the pas* sage connecting the ire-pot with the combustion-chamber, substantially as described.

7. In combination, a furnace provided at its top with a centrally-disposed outlet-flue, the inlet end whereof is located at a point below-the top of the furnace, a combustionchamber arranged furnace and having its upper portion surrounding the inlet end portion of the outletflue, a partition-wall extending across bein the upper part of said neath the receiving end of said outlet-flue and separating the latter from the combustion-chamber, an annulus supported within said coinbustioircliamber and dividing the interior thereof into annular circulating-passages, intersecting flues extending from portions of the circulating-passages exterior to the annulus, through said partition-wall and discharging into the receiving end of said outlet-flue, a fire-box provided with a restricted outlet discharging into the circulating-passages of the chamber at a point within the annulus and apassagev through said partitionwall whereby the products of combustion may be passed directly through the combustionchamber to a main outlet-flue without passing through the circulating-passages of the combustion-chamber', and a damper arranged to control said direct passage, substantially as described.

FRANCIS J. DOYLE.

Witnesses FREDERICK C. GOODWIN, ALBERT H. GRAvEs. 

